Tuyere



Feb. 12, 1957 :awr-:1R 2,781,190

TUYERE Filed March 9, 1951 FlELi- [mentar: Hen/VK WS/e,

United States TUYERE Application March 9, 1951, Serial No. 214,719

2 Claims. (Cl. 2156-41) This invention relates to tuyeres and moreparticularly to water cooled tuyeres for use in blast furnaces. Duringthe operation of a blast furnace the tuyeres discharge their blast ofair radially toward the centerV of the furnace and create an individualcombustion area immediately beyond the exit end of each tuyere. ln thetuyeres used prior to my invention there was a great deal of turbulenceadjacent the exit end of the tuyere which limited the penetration of theair into the furnace. Because of this and other reasons, a conoid coreof inactive materials occurs at the center of the hearth and extendsupwardly therefrom. it is of course desirable to reduce the size of thiscore as much as possible.

As the materials in the furnace burden are reduced and melted, they dropto the hearth in the form of iron or slag. These materials in a moltenstate till the hearth with the slag on top of the iron until the slagline rises to a level slightly below the underside of the tuyeres.

en this level is reached the furnace is cast. Since the air expandsradially in a swirling turbulence as it leaves the tuyere, descendingcoke and iron is driven across the nose of the tuyere causing abrasiveand thermal A destruction of the vertical surface thereof. Also theblast of air agitates the slag and creates a vertical, clockwiserotation of the upper strata thereof, thus causing the slag to Contactthe underside of the tuyere nose and adhere thereto. This slag with someiron therein attacks the 4- water cooled shell of the tuyere at thelowest part of the vertical face at the exit end and in many casescauses failure of the tuyere.

While the radial blowing mentioned above is that cornmonly used, it hasbeen suggested to use a non-radial circumferential blast and also adownward blast. The circurnferential blast has many of the disadvantagesof the radial blast. The designs of the prior downward blast types oftuyeres are such that the turbulent ow of the blast is aggravated. Alsoin many instances the degree 5- of curvature within the tuyere proper issuch that the view of the furnace interior is restricted and in someinstances eliminated. ln addition, cinder sometimes builds up in thetuyeres. l have found that the angles of declination suggested are inmost instances too great for best results.

l have found that tuyeres acquire an insulating and abrasive resistantcinderlike coating after they have been in use a relatively short time.This incrustation envelops the tuyere shell from the furnace wall towithin 6- an inch or two of the vertical surface of the upper nose fromwhence it recedes circumferentially to within six or eight inches of thefurnace wall at the underside of the tuyere. This formation occurs onlyin an area outside the inuence of the turbulent, abrasive combustionzone and protects the tuyere from failure.

In the tuyeres used prior to my invention there was danger of anexplosion occurring when the tuyere failed. Such explosions endangerfurnace personnel and equipment.

It is an object of my invention to provide a tuyere which exhausts ablast of air into the furnace with minimum turbulence.

Another object is to provide a tuyere having a minimum amount of itssurface within the turbulent abrasive com# bustion zone.

Still another object is to provide such a tuyere having an eicient,self-cleaning coolant system which in combination with the balancedangle ow of the blast prevents molten iron, slag and the like fromentering the tuyere.

A further object is to provide a tuyere of long life which alsoincreases the output of the furnace.

A still further object is to provide a tuyere which eliminates orgreatly restricts the danger of explosions when failure of the tuyereoccurs.

These and other objects will be more apparent after referring to thefollowing specification and attached drawings, in which: s

Figure 1 i-s a longitudinal section of the tuyere as placed in thetuyere cooler of a blast furnace;

Figure 2 is an enlarged longitudinal section of the tuyere;

Figure 3 is a sectional view taken on the line lll-Ill of Figure 2;

Figure 4 is a sectional View taken on the line lV-IV of Figure 2; and

Figure 5 is a perspective View of the tuyere.

Referring more particularly to the drawings, the reference numeral 2indicates that part of the furnace wall surrounding the tuyere cooler 4which suppnrts the tuyere 6 of my invention. The tuyere 6 consists of abody 8 made of a copper alloy or other appropriate material and havingan uninterrupted air passageway 10 therethrough for the admission of ablast of air to the furnace, this passage being connected at its inletend with the source of air supply by means of a pipe 12. Surrounding theair passageway 10 is a chamber 14 to which a cooling uid is supplied bymeans of an inlet pipe 16. The uid after passing through the chamber 14is discharged frorn the top thereof through an outlet pipe 18. The airpassageway 10 is inclined downwardly at an angle 20. The angle 20 ispreferably approximately 12 degrees but the tuyere will operatesatisfactorily when the angle is between 5 and l5 degrees. The -diameterof the passageway 10 is preferably greater at its entry end than at itsoutlet in order to gain the advantages of the nozzle elfect producedthereby. To minimize the vulnerable area of the lower tuyere nose and tocompensate for the angled blast passage, the height of the verticalsection 22 of the nose is reduced to a minimum commensurate withstructural and thermal conductivity requirements. This presentsavertical surface of 50 percent or less of that present in standardtuyeres. In combination with the angle flow of the blast this reducedsection oifers a lower tuyere nose of such proportion that the abrasiveagitation of the descending materials as well as the rotating motion ofthe top strata of liquid stag caused by the reduced turbulence of theblast, occurs below and out of contact with the tuyere, thus greatlyincreasing thelife of the tuyere. In order to obtain proper cooling andat the same time have a minimum vertical surface exposed to the adverseaction of the combustion area, the top part of the body 8 is providedwith a slightly sloping portion 24 which extends from the rear thereofto a point adjacent its exit or front end and a steep sloping portion 26extending from the portion 24 to a vertical top face 28. The height ofthe face 28 is approximately 11/2 times that of the section 22.

o The coolant chamber 14 is divided into a passageway 30 at its lowerend which is ,reduced in height and there- Vfore in cross sectional areaas it approaches the nose section'22. From the ypassageway 30 thecoolant water passes into Vthe main portion of the chamber 14. VA rib 32VisV located in the center of the upper nose portion in order to reduceYthe swirling, agitated, commingling of theopposed waters at the top ofthe tuyere. The rib 32 also strengthens the tuyere at a critical point.The coolant passes out through the passageway 18. This construction Vofthe coolant chamber causes the velocity of the cooling water to increaseto a maximum at the lower nose 22 from which area it passescircumferentially upwardlyvdecreasing in velocity as it rises to thewider upper portion of the chamber, The high velocity of the waiter atthe lower nose V22 prevents accumulation or' foreign materials on thechamber walls at this vulnerable location, while its rapid ow increasesthe cooling efliciency. YThe above construction of the tuyere is suchthat the insulating abrasive resistant coating mentioned above will formalong the tuyere roof tothe vertical position 2S with proportionateincreases about the balance of the shell.

vWhile one embodiment of my invention has been shown and described itwill be apparent that other adaptations and modications may be madewithout departing from the scope of the following claims.

I claim:

1. In a blast furnace, a substantially Vertical wall for said furnace, atuyere having its outer end adjacent the wall of the furnace and itsinner end extendingl into the furnace, said tuyere comprising a bodyhaving an air passage therethrough, said air passage being inclined funiformly downwardly and inwardly into the furnace from a point adjacentits outer end, Ythe axis of said air passage being arranged at an angleof between 5 and 15 degrees with the horizontal, said body having avertical wall surrounding the air passage outlet, said body having atop'portion sloping slightly downwardly and inwardly 4 Y, from its outerend and a portion merging withthe top portion andrsloping at arelatively steep angle downwardly to the top of the said wall, a coolingchamber in said body surrounding said passage, and a passageway in thelower part of said cooling chamber leading from its outer end to itsinner end and decreasing in cross section from its outer end to itsinner end, the inner end of said passageway having an opening into saidcooling chamber.

2. ln a blast furnace, a substantially vertical wall for said furnace, atuyere having its outer end adjacent the wall of the furnace and itsinner end extending into the furnace, said tuyere comprising a bodyhaving an air passage therethrough, said air passage beingrinclineduniformly downwardly and inwardly into the furnace from. a pointadjacent its outer end, the axis of said air passage' being arranged atan anglerof between 5 and 15 degrees with the horizontal, said bodyhaving a vertical wall A surrounding the air passage outlet, said bodyhaving a top portion sloping slightly downwardly and inwardly from itsouter end and a portion merging with the top portion andV sloping at arelatively steep angle downwardly to the top of the said wall, a coolingchamber in said body surrounding said passage, a rib in said chamberextending between the walls thereof at the steeply sloping portion ofsaid body, and a passageway in the lower part of said cooling chamberleading from its outer end to its inner end and decreasing in crosssection from its outer end to its inner end, the inner end of saidpassageway having an opening into said cooling chamber. Y

References Cited in the fle of this patent UNITED STATES PATENTSY296,225 Schulze-Berge Apr. 1, 1884 318,604r Devereux May 26, 18851,205,568 Ross, Jr Nov. 21, 1916 1,354,032 Dovel Sept. 28, 19201,994,115 Y Stoecker Mar. 12, 1935V 2,124,437 Steinbacher July 19, 19382,501,265 Diaz Mar. 21, 1950

